Plymouth plantation was founded by people who came to America for religious freedom. Since they were outside of the English laws, they had to come up with their own set of laws which they finally published in 1636. Also, they weren't a chartered English colony, they formed the Mayflower Compact. And later, the charter became a problem. Since they didn't have a formal charter, they had to merge with the Massachusets Bay colony in 1692. Also, since they didn't have a connection with any country in Europe, they were not able to trade for needed items, but Native Americans like Squanto the Pilgrims survive.
Hope that helped. :)
